Metals by Micro-Scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties

A. Reiser; L. Koch; K. A. Dunn; T. Matsuura; F. Iwata; O. Fogel; Z. Kotler; N. Zhou; K. Charipar; A. Piqué; P. Rohner; D. Poulikakos; S. Lee; S. K. Seol; I. Utke; C. van Nisselroy; T. Zambelli; J. M. Wheeler; R. Spolenak

Advanced Functional Materials 30 (2020) 1910491-1910491

Abstract Many emerging applications in microscale engineering rely on the fabrication of 3D architectures in inorganic materials. Small-scale additive manufacturing (AM) aspires to provide flexible and facile access to these geometries. Yet, the synthesis of device-grade inorganic materials is still a key challenge toward the implementation of AM in microfabrication. Here, a comprehensive overview of the microstructural and mechanical properties of metals fabricated by most state-of-the-art AM methods that offer a spatial resolution ≤10 ?m is presented. Standardized sets of samples are studied by cross-sectional electron microscopy, nanoindentation, and microcompression. It is shown that current microscale AM techniques synthesize metals with a wide range of microstructures and elastic and plastic properties, including materials of dense and crystalline microstructure with excellent mechanical properties that compare well to those of thin-film nanocrystalline materials. The large variation in materials’ performance can be related to the individual microstructure, which in turn is coupled to the various physico-chemical principles exploited by the different printing methods. The study provides practical guidelines for users of small-scale additive methods and establishes a baseline for the future optimization of the properties of printed metallic objects?a significant step toward the potential establishment of AM techniques in microfabrication.